1 // RUN: %clangxx_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
2 #include "test.h"
3 
4 int *g;
5 
6 void *Thread(void *a) {
7   int *p = 0;
8   while ((p = __atomic_load_n(&g, __ATOMIC_RELAXED)) == 0)
9     usleep(100);  // spin-wait
10   *p = 42;
11   return 0;
12 }
13 
14 int main() {
15   pthread_t t;
16   pthread_create(&t, 0, Thread, 0);
17   AnnotateIgnoreWritesBegin(__FILE__, __LINE__);
18   int *p = new int(0);
19   AnnotateIgnoreWritesEnd(__FILE__, __LINE__);
20   __atomic_store_n(&g, p, __ATOMIC_RELAXED);
21   pthread_join(t, 0);
22   delete p;
23   fprintf(stderr, "OK\n");
24   return 0;
25 }
26 
27 // CHECK-NOT: WARNING: ThreadSanitizer: data race
28 // CHECK: OK
29